English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The potential role of magnetic fields and cosmic ray propagation for feedbackprocesses in the early Universe can be probed by studies of local starburstcounterparts with an equivalent star-formation rate. Archival data from theWSRT was reduced and a new calibration technique introduced to reach the highdynamic ranges needed for the complex source morphology of M82. This data wascombined with archival VLA data, yielding total power maps at 3cm, 6cm, 22cmand 92cm. The data shows a confinement of the emission at wavelengths of 3/6cmto the core region and a largely extended halo reaching up to 4kpc away fromthe galaxy midplane at wavelengths of 22/92cm up to a sensitivity limit of90muJy and 1.8mJy respectively. The results are used to calculate the magneticfield strength in the core region to 98muG and to 24muG in the halo regions.From the observation of free-free losses the filling factor of the ionisedmedium could be estimated to 2%. We find that the radio emission from the coreregion is dominated by very dense HII-regions and supernova remnants, while thesurrounding medium is filled with hot X-ray and neutral gas. Cosmic raysradiating at frequencies higher than 1.4 GHz are suffering from highsynchrotron and inverse Compton losses in the core region and are not able toreach the halo. Even the cosmic rays radiating at longer wavelengths are onlyable to build up the observed kpc sized halo, when several starbursting periodsare assumed where the photon field density varies by an order of magnitude.These findings together with the strong correlation between Halpha, PAH+, andour radio continuum data suggests a magnetic field which is frozen into theionised medium and driven out of the galaxy kinematically.

M82 - A radio continuum and polarisation study I. Data reduction and cosmic ray propagation